The proposed study, of The Epidemiology and Cost of EMS Provided to Children" will be a population-based study of all Utah EMS runs and related hospital records in persons age 18 and younger for 1991-92. The study was designed to meet research needs concerning emergency medical services for children (EMSC) identified in a 1993 Institute of Medicine report. The study will build upon a previous research effort at the University of Utah funded by the U.S. Department of Transportation which looked at injuries related to motor vehicle crashes in 1991-92. Much of the necessary data has already been acquired and data-sharing agreements are in place for the remaining records. EMS, hospital outpatient, inpatient, regional poison center, and police crash records will be matched using probabilistic matching software developed for the U.S. Census. The study will be population-based and will: a) describe the epidemiology of pediatric emergencies which utilize the EMS system (EMSC)1 determine the cost of EMSC and related hospital care, examine the effect of EMS care and intervention on patient outcome determine the cost and nature of EMSC aeromedical transport, to determine the effect of poison control center telephone consultation on subsequent EMSC and hospital care. The epidemiology of EMSC for racially ethnic groups, children with special needs, urban versus rural areas, and for type of EMS available, will be defined both for trauma and for detailed categories of pediatric illness. The study will include an outcome analysis of EMSC and will compare the care give by advanced life support (ALS) EMS units before and after EMSC training, which took plaCe in Utah in early 1992. Separate analyses of EMSC care will be done for victims of motor vehicle crashes, children with respiratory illness, and children with poisoning.